Field of the Invention
The present invention relates to a thermally conductive sheet used as a sheet or the like interposed between a heat generator and a heat radiator for efficiently conducting heat from the heat generator to the heat radiator, and to a thermally conductive resin composition for forming the same.
Description of the Background Art
A thermally conductive sheet has conventionally been arranged between a heat generator such as electronic components and a heat radiator (a heat radiating member or a cooling member), as means for efficiently dissipating heat generated in various apparatuses or electronic devices to the outside. By interposing a thermally conductive sheet having flexibility and high heat conduction performance, a heat generator and a heat radiator can be coupled to each other with good adhesive force, with the thermally conductive sheet high in heat conduction performance being interposed. Therefore, consequently, as compared with a case where a thermally conductive sheet is not interposed, efficiency in heat conduction from a heat generator to a heat radiator can be improved.
Many of thermally conductive sheets currently commercially available in general are silicone rubber sheets mainly composed of silicon. It has been well known, however, that the thermally conductive sheet made of silicone rubber gives rise to a problem of pollution of a system due to volatilization of a low-molecular-weight siloxane component contained in the sheet. In addition, recently, in particular in a market for semiconductor manufacturing apparatuses or for power devices, a thermally conductive sheet which withstands use at a high temperature of 200° C. or higher has been demanded, however, the thermally conductive sheet made of silicone rubber has currently been challenged by a problem also of such heat resistance.
In order to solve the problems above, Japanese Patent Laying-Open No. 2010-232535 has proposed use as a thermally conductive sheet (a heat-resistant heat radiation sheet), of a fluororubber sheet mainly composed of fluorine, which is obtained by causing reaction and curing of a mixture of liquid fluorinated polyether and a thermally conductive filler.